The Hyper Pet 4 Pack of Balls for Dogs are designed with your furbaby’s safety in mind. Unlike traditional tennis balls, these tennis balls are made of grade A rubber. They’re safe on your pup’s teeth and are free of harmful coatings or gasses, so you can feel confident about playtime with your best friend. These balls even float, so take them to the lake or play with them in the pool. The balls are compatible with Hyper Pet products like the Hyper Flink or K-9 Kannon (sold separately), or just play with them on their own for paw-some fun.